Soft ice cream is normally dispensed at the point of sale from a soft serve ice cream machine, i.e. a semi-continuous, pressurised scraped surface heat exchanger in which a pre-packaged mix is frozen and aerated. It is typically dispensed at temperatures of −4 to −8° C., for example into a cone, and is then immediately consumed. It is liked by many consumers because of its texture, which is softer than that of ice cream served by scooping from a container kept in a freezer cabinet at around −18° C. Soft serve ice cream machines have a number of disadvantages: they are large and expensive, require training to operate, consume considerable energy, do not deliver consistent product quality if used over a period of time and are inconvenient for the operator to dismantle and clean. Each machine can also only offer one type of product (e.g. flavour/ice cream/sorbet etc) at a time—separate freezer barrels are required for different products.
In recent years, systems for dispensing soft ice cream have been developed in which pre-packaged ice cream is delivered from a container by a dispensing apparatus. US 2006/255066 discloses a dispensing apparatus containing a pressure-displacement device that forces the food (such as soft ice cream) out of its container. The container is located within a chamber which keeps the ice cream at a specified temperature between −6 and −24° C. A plunger is used to push the ice cream out of the container through a self-closing valve.
Nonetheless, there remains a need for an improved system for dispensing soft ice cream. More particularly, such improved system must allow for consistent good quality dispensing irrespective of:                the temperature of the ice cream which, even a well controlled cabinets, can range from −16° C. and −21° C., leading to huge viscosity variations        the composition/flavour of the ice cream which again leads to significant rheological changes, even at constant temperature.        